Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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UTILITY PATENT APPLICATION
OF
BENJAMIN J. KREMPEL
FOR
PUMPING MECHANISM INSERT
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from US Provisional Patent Application
62/635195 filed
02/26/2018, which is incorporated herein by reference. This application claims
priority from
US Provisional Patent Application 62/658855 filed 04/17/2018, which is
incorporated herein
by reference.
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FIELD OF THE INVENTION
The current invention relates to pneumatic tire inflation. More particularly,
the invention
relates to at self-inflating pneumatic tire having a compression layer
disposed between a tire
casing and tire tread.
BACKGROUND OF THE INVENTION
One of the most efficient pumping designs for self-inflating tires for
bicycles is to put the
lumen outside of the tread of the tire and centered in the middle of the tire.
With this design,
the hard, stiff tire compresses the pumping mechanism against the hard
pavement. This
design is very efficient because most of the load on the wheel presses down on
the pavement
and therefore on the pumping mechanism. However with this type of design,
there are several
problems such as the tire ride quality is compromised because the pumping
mechanism has
a high ridge along the riding surface of the tire and therefore is prone to
tracking or can be
easily torn, ripped, damaged by elements on the riding surface. A further
problem is low
durability of the pumping mechanism due to thin wall thickness of the pumping
mechanism,
and current tire manufacturing processes do not lend themselves to high
precision features,
such as a pumping mechanism, withstanding the injection molding and
vulcanization cycles.
What is needed is a self-inflating pneumatic tire having the compression
mechanism disposed
between the tire casing and tire tread.
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SUMMARY OF THE INVENTION
To address the needs in the art, self-inflating tire is provided that includes
a pneumatic tire
having a tread, and a casing, where the tread includes an outer riding
surface, where the
casing includes an inner inflation surface, and an elastic inflation lumen
disposed between
the casing and the tread, where the inflation lumen has at least one air
through-port.
On one aspect of the invention, the at least one air through-port includes an
input port, an
output port, or an input/output port (I/O port).
In another aspect of the invention, the inflation lumen includes a closed-end
inflation lumen
that spans along at least a portion of a circumference of the pneumatic tire.
According to a further aspect of the invention, the inflation lumen includes
an open-end
inflation lumen that spans along a circumference of the pneumatic tire.
In one aspect of the invention, the tread includes a channel, where the
inflation lumen is
disposed in the channel.
In yet another aspect of the invention, the pumping mechanism is configured to
a tire
according to a tubeless tire, or a tubed tire.
According to another aspect, the invention further includes a compression
layer that is
disposed in a position that includes between the inflation lumen and the
tread, or between the
casing and the inflation lumen, where the compression layer includes an
actuator, where the
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actuator has a cross-section having a base and a converging tip, where the
converging tip
abuts an outer surface of the inflation lumen, where the compression layer has
a length that
spans along at least a portion of a circumference of a pneumatic tire. In one
aspect, the
actuator includes at least one ridge feature on the converging tip that is
transverse to the
compression layer length. In another aspect, the compression layer includes an
interlocking
actuator, where the interlocking actuator has a female actuator disposed on a
first side of the
inflation lumen and a male actuator disposed on a second side of the inflation
lumen, where
the first side is opposite the second side, where the interlocking actuator is
configured to
impart a surrounding-force directed to maintain alignment between the
inflation lumen and
the actuator. In a further aspect, the compression layer includes a lower
hardness than a
hardness of the tread.
According to one aspect of the invention, the inflation lumen is disposed
along at least a
portion of a circumference of the pneumatic tire.
In another aspect the invention further includes an inflation lumen protection
layer disposed
between the inflation lumen and the tread.
In a further aspect of the invention, the inflation lumen includes a block
shape cross-section,
where the block shape cross-section has a channel forming the lumen.
According to one aspect, the invention further includes a valve, where the
valve includes a
membrane valve, a 3-way valve, or a 2-way valve. In one aspect, the current
embodiment
further includes a connector tubing disposed between the lumen and the valve.
In one aspect,
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the connector tubing includes an accumulator, where the accumulator stores a
volume of air
between the lumen and the valve. In a further aspect, the valve is connected
to an inner tube,
where the inner tube connection includes a controller connected between the
inflation lumen
and the valve of the inner tube.
According to one aspect, the invention further includes a valve and an
actuator pressure
governor, where the actuator pressure governor has an adjustable air
input/output port.
In another aspect, the invention further includes a controller that includes a
removable
controller, an adjustable pressure controller, or a fixed pressure controller.
In one aspect, the
controller is disposed in a location inside an inner tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGs. IA-1B
show a self-inflating tire system that includes a tire casing, a tire tread,
an
inflation lumen, and an compression layer, where the inflation lumen is
disposed between the casing and the tread, according to one embodiment of
the invention.
FIGs. 2A-2F show the inflation lumen embodied in a housing having a block-
shape cross-
section, according to one embodiment of the invention.
FIGs. 3A-3B show a pumping mechanism that includes the inflation lumen, and
the
compression layer fittably inserted between the casing and tread to a lumen
channel, according to one embodiment of the invention.
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FIGs. 4A-4B show one embodiment of the compression layer, according to one
embodiment of the invention.
FIGs. 5A-5B show a compression layer incorporated between the casing and
tread, where
the compression layer includes interlocking features, according to one
embodiment of the invention.
FIGs. 6A-6C show a closed-end pumping mechanism, according to one embodiment
of
the invention.
FIGs. 7A-7B show a three-way valve in a controller, where the three-way valve
is
constructed by utilizing two standard tire check valves, according to one
embodiment of the invention.
FIGs. 8A-8B show how the closed-end pumping mechanism can be optimized in
different
ways compared the open-end systems because of its different operating
principle, according to one embodiment of the invention.
FIGs. 9A-9D show an adjustable pressure diaphragm valve for an adjustable
pressure
valve, according to one embodiment of the invention.
FIGs. 10A-10D show an adjustable pressure diaphragm valves for an adjustable
pressure
valve, according to one embodiment of the invention.
FIGs. 11A-11D show alternate embodiments of the tire port connections,
according to one
embodiment of the invention.
DETAILED DESCRIPTION
The invention provides a self-inflating tire system and a pressure regulation
system for self-
inflating bicycle tires, which controls the air pressure in the system. The
self-inflating tire
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system uses mechanical energy from the rolling and deformation of the tire to
push air into
the tire. Once the desired pressure is reached the pressure regulation system
stops the system
from pumping.
According to one embodiment, the pumping mechanism is manufactured separately
from the
tire, where the pumping mechanism includes a compression lumen and control
system, where
the tire is designed with features for accepting the pumping mechanism. In
this embodiment,
the pumping mechanism is designed to be integrated into the tire to provide a
uniform riding
surface having sufficient rubber on the riding surface to protect the pumping
mechanism from
harm for the designed tire life. In this embodiment, the pumping mechanism
includes a
lumen within a polymer or rubber bulk layer, where the compression lumen is
disposed
circumferentially to an outer surface of a tire casing, yet embedded with or
beneath the tire
tread. In this example, the compression lumen is incorporated with the tire
tread according
to vulcanization, adhesion, extrusion, or molding technologies.
According to other aspects, the invention further includes a compression layer
that is
disposed in a position that includes between the inflation lumen and the
tread, or between the
casing and the inflation lumen, where the compression layer includes an
actuator, where the
actuator has a cross-section having a base and a converging tip, where the
converging tip
abuts an outer surface of the inflation lumen, where the compression layer has
a length that
spans along at least a portion of a circumference of pneumatic tire. In one
aspect, the actuator
includes at least one ridge feature on the converging tip that is transverse
to the compression
layer length. In another aspect, the compression layer includes an
interlocking actuator,
where the interlocking actuator has a female actuator disposed on a first side
of the inflation
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lumen and a male actuator disposed on a second side of the inflation lumen,
where the first
side is opposite the second side, where the interlocking actuator is configure
to impart a
surrounding-force on the inflation lumen. In a further aspect, the compression
layer includes
a lower hardness than a hardness of the tire.
Turning now to the pumping mechanism, the current invention provides a pumping
mechanism between the casing and the tread of the tire. Pneumatic tires such
as bicycle tires
carry their load through the tension of the fibers in the casing. This tension
plus the
surrounding materials create a stiff, but pliable region. The current
invention places a
pumping mechanism between the outer surface of the casing and the tread. The
load imparted
on the tire is transferred from the casing to the pumping mechanism, where the
pumping
mechanism compresses as the tire rolls on the ground surface. These dynamics
causes the
lumen to collapse and push air forward through the lumen and into the control
system. As
the wheel rotates, the load is removed from the pumping mechanism and the
lumen rebounds
to its original shape, where air is drawn in for the next pumping cycle.
Turning now to the figures, FIGs. 1A-1B show an example of one embodiment of
the
invention, where shown is the self-inflating tire system 100, that includes a
tire casing 102
(also referred to as a carcass), a tire tread 104, an inflation lumen 106, and
an compression
layer 108 that includes an actuator 112. Here, the inflation lumen 106 is
disposed between
the casing 102 and the tread 104, where the compression layer 108 has a
protection layer 110
for positioning and retaining the inflation lumen 106 at a desired position
along the outer
surface of the casing 102, and an actuator tip 112 having a base that
converges at the top (see
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FIG. 1B). In the current embodiment, the inflation lumen 106, the compression
layer 108
and the protection layer 110 are collectively referred to as the pumping
mechanism 200.
According to the current invention, the inflation lumen 106 material includes
any one of, or
a combination of: natural rubber, synthetic rubber, high molecular weight,
flexible polyvinyl
chloride (PVC), standard flexible PVC, peroxide cured silicone, thermoplastic
vulcanizate
(TPV), and thermoplastic elastomer (TPE) Viton TM rubber.
According to the current invention, the compression layer 108 material
includes any one of,
or a combination of foamed natural rubber, foamed synthetic rubber, foamed
thermoplastic
PU, foamed polyurethane, open cell foam, and closed cell foam.
There are many benefits to this construction. For example, separate
construction of the
pumping mechanism 200 and tire allows much more complexity to be built into
the tire
assembly. Typically, tires go through a vulcanization process where high heat
and pressure
force the unformed, unvulcanized rubber into the shape and profile of the
finished product.
Delicate elements such as the pumping mechanism 200 would otherwise have
difficulty
withstanding the high heat and pressure of the process without deformation.
Another advantage of the current invention is that the pumping mechanism 200
is uniform
around the major circumference, or at least a portion of the circumference of
the wheel; this
maintains the uniform riding surface of the tire, resulting in a high quality
of ride.
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FIGs. 2A-2F show another embodiment of the invention, where the inflation
lumen 106 is
embodied in a housing 202 having block-shape cross-section. Further shown is a
soft
rebound material 206, where the soft rebound material 206 can be a foam
material or an air
pocket. The pumping mechanism 200 must also have the compression layer 108.
This
includes an open space, or a rebound material 206 made of a relatively easily
compacting
material that concentrates and focuses the load of the tire on the inflation
lumen 106,
compression layer 108, and actuator tip 112. In this way, a sufficiently large
amount of force
can be utilized to collapse the inflation lumen 106. The rebound material 206
may be a space
or it may be one or more materials that occupy the space such as foam, air or
other easily
crushable, compressible materials. FIGs. 2C-2D show the rebound material 206
as a foam
or elastic material that can be located surrounding, or anywhere near the
inflation lumen 106
and the compression layer 108. The wider the compression layer 108 and rebound
material
202, the more downward force that can be captured to compress the inflation
lumen 106. The
rebound material 202 also reduces the tires resistance to lateral forces
during riding and so
must be designed with both tire handling and pumping efficiency in mind. FIGs.
2E-2F
show a further embodiment of the invention, where the inflation lumen 106
further includes
stabilizing features 208 disposed horizontally on opposing sides of the
inflation lumen 106.
In this embodiment, the compression layer 108 and inflation lumen 106 are
disposed between
the tire casing 102 and the tread 104, where the compression layer 108 abuts
an intermediary
.. casing layer 210. The embodiment shown in FIGs. 2E-2F do not require the
actuator tip
112, where the compression layer 108 envelopes the inflation lumen 106 and
fittedly
surrounds the stabilizing features 208 to position the inflation lumen 106 to
the center of the
compression layer 108 for optimum compression. In FIGs. 2E-2F, the compression
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108 captures the inflation lumen 106 horizontally and then presses on the
inflation lumen
106 from the top and bottom surfaces.
The compression layer with a raised surface and block lumen, such as in FIGs.
2A-2D are
an advantageous design because the inflation lumen 106 and actuator tip 112
can be
configured to almost any geometry and cross-sectional area. The smaller the
inflation lumen
106 cross-section, the less force and travel required to compress the air in
the inflation lumen
106. This embodiment could be advantageous in high-use applications or
applications where
it is advantageous to minimize the size of the pumping mechanism. Embodiments
with a
tube configured inflation lumen 106, that is, where the inflation lumen 106
has distinct inside
diameters and outside diameters are limited in their durability and pressure
ratings due to the
thickness of the tube wall. Tubes with thicker wall thickness are more durable
but also
require more force to compress. The block inflation lumen 106 as shown in
FIGs. 2A-2D
have relatively thick wall construction on all sides except for where it
contacts the raised
surface of the actuator tip 112. This embodiment therefore permits smaller
inflation lumen
106 cross sectional areas without increasing the force required to compress
the inflation
lumen 106 or reducing the durability of the pumping mechanism 200.
In another embodiment of the invention the tread may have different layers of
materials. For
example different layers to indicate wear. This can be done through different
layers of
multicolor rubber. For example the color may start out black then go to yellow
then to red.
Other layered materials may include Kevlar or other reinforcement material to
protect against
puncture.
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FIGs. 3A-3B show a further embodiment of the invention, where the pumping
mechanism
200 includes the inflation lumen 106, and the compression layer 108. In the
current
embodiment, the pumping mechanism 200 is fittably inserted between the casing
102 and
tread 104 to a lumen channel 204 through an open seam in the outer tread 104,
where the
seam is then bonded to encase the pumping mechanism 200.
FIGs. 4A-4B show one embodiment of the compression layer 108 and actuator 112.
FIG.
4B shows a perspective view of the compression layer 108, where the actuator
tip 112 is
shown having a series of tip ridges 300 configured to sequentially actuate and
compress the
inflation lumen 106 as the wheel rolls on a surface. The tip ridges 300
enhance the efficiency
in the movement of the air along the inflation lumen 106, where the raised
surfaces of the tip
ridges 300 ensure that the inflation lumen 106 closes and seals and therefore
pushes the air
forward, which is especially useful in road bike and other high-pressure
applications.
FIG. 5A shows a compression layer 108 having a protection layer 110 region
disposed
between the casing 102 and the inflation lumen 106, where the inflation lumen
106 remains
incorporated between the casing 102 and tread 104. In this embodiment, the
compression
layer 108 includes interlocking features 500a/500b. The interlocking features
500a/500b
facilitate in focusing the compression energy of the actuator tip 112 directly
onto the
compression lumen 106, while preventing any misalignment of the actuator tip
112 on the
compression lumen 106 when the tire rolls along an off-camber, angled, or
rough surfaces.
The inflation lumen 106 is an elastic and compressible tube which provides the
spring force
for drawing in air in the intake cycle. During the compression cycle, the
inflation lumen 106
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is compressed, which pushes the air through the system. To have a balanced and
uniform
wheel, it is desirable to have the inflation lumen 106 completely encircle the
outside of casing
102 and beneath the tread 104. However, it can completely encircle the casing
102 or only
partially encircle the casing 102. The inflation lumen 106 can also completely
encircle the
casing 102 but only be active for a portion of its length. For the closed-end
inflation lumen
106, for example, the active section shown in the drawing only occupies 180-
degrees. The
other 180-degrees of the inflation lumen 106 would be of similar density and
material so that
there is no noticeable difference between the two sections for the rider.
The compression layer 108 and actuator tip 112 push on the inflation lumen 106
from one or
more sides to cause it to compress. The actuator tip 112 may be a raised
surface as shown in
FIGs. 2A-2D where it pushes into the lumen from only one side to compress it.
In other
embodiments such as the embodiment shown in FIGs. 5A-5B the compression layer
108 and
actuator tip 112 pushes on the inflation lumen 106 from multiple sides.
An open-end pumping mechanism is shown in FIG. 8A. In this embodiment, the
open-end
pumping mechanism has two ports for the air to both enter and exit. That is to
say air enters
through a first port, is compressed, and then exits through a second port. In
some designs
the port is a dedicated entrance and a dedicated exit. In other embodiments
the two ports are
interchangeable and the function of the port is dependent upon the orientation
of the tire.
Ideally, the pumping mechanism completely encircles the major diameter of the
tire. This is
beneficial because it preserves the uniform ride of the tire. It is possible,
however, to limit
the active section of the pumping mechanism. This would be desirable in high
usage
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applications for example where the pumping mechanism has a pumping volume much
greater
than that required to offset air loss from diffusion. Bike sharing would be an
example of this.
In this case the active length of the pumping mechanism could be reduced to
any fraction of
the circumference, for example 120-degrees or 180-degrees of the tire major
diameter. This
would also reduce the incidence of puncture and increase reliability because a
portion of the
pumping mechanism would no longer be susceptible to puncture.
The current invention includes a closed-end pumping mechanism shown in FIG. 8B
and
FIGs. 7A-7B, where there is only a single port connecting the pumping
mechanism 200 to a
controller 600, where only the inflation lumen 106 of the pumping mechanism is
shown for
clarity of illustration. In this embodiment air is drawn in through the valve
stem 602 and into
the inflation lumen 106 of the pumping mechanism. The flow of air is reversed
during the
compression cycle and a three-way valve redirects the flow of air into the
tire.
Essentially, the air in the inflation lumen 106 is compressed and pushed out
of the inflation
lumen 106 from the same end it entered the inflation lumen 106. This design
significantly
reduces the complexity of the pneumatic circuit because is it only requires
one pneumatic
passageway between the tire and the controller. Having only one passageway
through the
tire opens up great flexibility of the connection between the tire and the
inner tube.
FIGs. 7A-7B show one embodiment of the invention that includes a three-way
valve in the
controller 600, where the three-way valve is constructed by utilizing two
check valves. In
this case the first check valve is pneumatically connected to the atmosphere
on one side and
pneumatically connected to the closed-end inflation lumen 106 and the second
check valve
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on the other side. The second check valve pneumatically connects the inflation
lumen 106
and the first check valve on one side and the pressurized chamber of the tire
on the other side.
In some cases there is an air accumulator located where the first check valve,
the second
check valve and the closed-end inflation lumen 106 join. In some embodiments a
connector
tubing joins the inflation lumen 106 to an accumulator 604, where
alternatively, the
connector tube is large enough to at least partially perform the function of
an accumulator
604. The accumulator 604 allows the three elements to physically connect and
improves the
performance of the valves' actuation by allowing a greater mass of air to
collect and operate
the valves. When the inflation lumen 106 is compressed and released, it
creates a vacuum,
.. which opens the first check valve. Atmospheric air is drawn in through the
valve stem and
passes through the first check valve. The inflation lumen 106 fills up with
air during the
rotation of the tire. The tire continues to rotate and soon begins to compress
the inflation
lumen 106 starting with the closed end. As the air in the inflation lumen 106
is compressed,
it locks the first check valve closed. The pressure in the inflation lumen 106
builds until it is
great enough to open the second check valve, which pushes air into the chamber
of the tire.
Once the tire rolls past the open-end of the inflation lumen 106 the lumen
begins to pull in
air and drops the air pressure at both check valves. The pressure drop causes
the first check
valve to open and the second check valve to close. The cycle then starts
again.
The elements of the three-way control valve can be located anywhere in the
system. For
example in the embodiment shown in FIGs. 7A-7B both check valves, the
accumulator 604
and the connector tubing 606 are all located near the valve stem at the top of
the inner tube.
However the design could also have the three-way valve closer to the riding
surface if that
was determined to be beneficial. The positioning of the two check valves could
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multiple configurations. For example in FIGs. 7A-7B the check valves are at 90
degrees to
each other. They could also be vertically positioned inline or even
horizontally positioned.
Ideally the connector tubing is as short as possible because the air in the
length of the
connector tubing 606 is not compressed by the pumping mechanism 200 during
operation
and therefore leads to performance losses. The cross-sectional area of the
connector tubing
can also be larger than the cross-sectional area of the lumen so that the
connector tubing acts
as an accumulator. This could minimize the combined volume of the connector
tubing and
accumulator and allow the system to operate more efficiently. In one
embodiment the
connector tubing 606 is bellowed to offer stress relief the connector tubing
606 and to
minimize the length of the tubing at the same time.
FIGs. 8A-8B show how the closed-end pumping mechanism can be optimized in
different
ways compared the open-end systems because of its different operating
principle. For
example the pumping cycle in both types must fist draw in air from the
atmosphere and
second push compressed air into the tire chamber. The open-end pumping
mechanism is able
to do both of these steps in parallel. As soon as a section of inflation lumen
106 passes the
contact patch, the inflation lumen 106 immediately begins to draw in air again
from the
atmosphere. And so, as shown in FIG. 8A, one rotation of the tire yields
almost 360 degrees
of both drawing in air and pushing compresses air into the tire chamber. The
closed-end
system, however, performs both of these functions in series. For example if
the active,
closed-end pumping mechanism goes half way around the tire or 180 degrees,
then the
inflation lumen 106 will draw in air for 180 degrees and push compressed air
into the tire for
180 degrees. In this scenario comparing the two pumping mechanisms, the open-
end
pumping mechanism will pump twice as much air per revolution as the closed-end
system.
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This is because the closed end inflation lumen 106 extends only 180 degrees as
compared to
360 degrees for the open-end system. FIG. 8B shows a closed-end pumping
mechanism that
goes completely around the tire and only has 180-degrees of active pumping
mechanism.
The closed-end system needs some dwell time to allow air to be sucked into the
system. In
spite of the different operating principles, the closed-end pumping system is
still
advantageous because most cycling applications do not require a large air
pumping capacity.
Diffusion acts very slowly so in most cases even a limited cycling distance is
enough to bring
the tire pressure back to the desired range.
1() Another important aspect of the closed-end pumping mechanism is that it
does not need to
be unbalanced. The pumping mechanism may go completely around the tire or it
may go
partially around the tire. A pumping mechanism can be designed to completely
encircle the
tire and only have a portion of the pumping mechanism active. In this way the
invention can
be optimized for uniform ride, balance and ease of manufacturing while at the
same time
.. limiting the degrees or length of the active pumping mechanism. The
inflation lumen 106 of
the pumping mechanism 200 could be plugged, clamped, glued, terminated or use
any other
method to limit the length of the active pumping mechanism.
The pumping mechanism 200 can be similar in form to open-end designs in that
it can be
slightly stretched and then glued or vulcanized into place in the channel on
the tire (see FIGs.
3A-3B for example). The pumping mechanism 200 can be permanently attached to
the tire
or releaseably attached to the tire. It can be located in a channel in the
tire as shown in FIGs.
3A-3B or underneath the complete tread. The pumping mechanism 200 can be
located and
assembled in any other manner that is being used by open-end pumping
mechanisms.
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Although the closed-end inflation lumen 106 design can be used for almost any
self-inflating
tire, the invention has been shown in the embodiment where the pumping
mechanism 200 is
located outside the casing 102 of the tire. The pumping mechanism 200 connects
to the inner
tube through a single port, which passes through the casing of the tire. The
inner tube
contains a corresponding port so that the pneumatic connection between the
inner tube and
tire is made. In one embodiment the male connector is part of the pumping
mechanism 200
and the female connector is part of the inner tube. In other embodiments the
male/female
connectors can be reversed. Having the male connector attached to the pumping
mechanism
.. 200 has the advantage of not introducing any raised elements outside of the
casing and
therefore potentially offers a smoother ride. In the case where the
application is tubeless all
of the same elements are included in the system only they are not packaged
within an inner
tube.
.. The current invention uses flexible tubing to join the different elements
together. The overall
flow of air through the system can be seen in FIGs. 8A-8B the air control
circuit diagram.
The diagram shows the overall flow of air into the system beginning with air
entering the
valve stem and finishing with the air entering the inner tube or pressurized
chamber of the
tire. Air enters through the valve stem and into a first air passageway in the
control module.
The first air passageway in the control module provides a conduit for the air
to the low-
pressure lumen. The control module controls whether the first air passageway
is open or
closed. If the first air passageway is open, air can entire the system and
increase the pressure
in the tire. If the first air passageway is closed no air can enter the
system. Air leaves enters
the low-pressure lumen and connects to the pumping mechanism. As the tire
rolls on the
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pavement, the air is compressed in the pumping mechanism and exits the pumping
mechanism into the high-pressure lumen. The high-pressure lumen transfers the
air to a
second air passageway located in the control module. The second air passageway
terminates
with a check valve mounted in the control module.
FIGs. 9A-9D and FIGs. 10A-10D show some example embodiments of different
adjustable
pressure diaphragm valves, where FIGs. 9A-9D show an adjustable pressure
presta valve for
a closed-end pumping mechanism, and FIGs. 10A-10D show an adjustable pressure
presta
valve for an open-end pumping mechanism. Here the valve includes an actuator
pressure
governor, where the actuator pressure governor has an adjustable air
input/output port.
The tires used is this system can be manufactured on current equipment found
in industry.
That is to say they are of the same standard sizes and use the same
construction methods.
Because most of the high precision elements of the system are located in the
pumping
mechanism, the manufacturing processes for the tire remains mostly unchanged.
In the
embodiments where the tire has a channel to accept the pumping mechanism. The
channel
is approximately 5-20mm wide. In certain embodiments, the pumping mechanism is
adhered
in its position in the between the casing and the tread either through
vulcanization or
adhesion.
One of the advantages of the system is that that self-inflating tire can be
manufactured on
existing industry equipment. Typically, in bicycle tire manufacturing the
components of the
tire including casing, bead and tread rubber are assembled and then placed in
a mold for
vulcanization. The heat and pressure from the mold force the rubber into its
final shape and
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the raised edges and profile of the tread are formed. The typical
vulcanization process would
damage the pumping mechanism so the invention uses two methods to incorporate
the
pumping mechanism into the tire.
In the first method the casing of the tire and the tread are assembled and
vulcanized
independently of each other. FIGs. 2B-2D show exploded views of the tread 104,
pumping
mechanism 200 and the tire tread 104. In these embodiments, the pumping
mechanism 200
is assembled and joined to the tread 104. The pumping mechanism-tread assembly
is then
joined to the casing 102. The elements can be joined using adhesive or
vulcanization
techniques already found in the tire industry. For example, some bicycle tires
already adhere
the tread to the tire post-vulcanization. The trucking industry uses these
same techniques to
retread tires.
The second method of assembly is shown in FIGs. 3A-3B, which form the tire all
in one
piece, including the tread, and create a cavity for the pumping mechanism.
FIG. 3B shows
the tire cross-section with the pumping mechanism cavity 204 in the open
position. The
pumping mechanism 200 is then placed into position in the cavity and the seam
is joined
either through the use of adhesives or vulcanization. This method is
advantageous in that it
allows the entire tire, including the tread, to be vulcanized at the same
time. It also allows
the same rubber compounds to be used for the tread 104 and casing 102.
The self-inflating tire has one or more ports to pneumatically join the tire
to the inner tube.
The in this embodiment, the ports include a tire low-pressure port and a tire
high-pressure
port. FIG. 11A, where FIGs. 11A-11D show alternate embodiments of the tire
port
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connections. In the case where the design is inner tubeless, the tire ports
pneumatically attach
directly to the connector tubing 606. The tire ports in one embodiment are
barbed connectors
made of high durometer materials such as plastic or metal that are co-
manufactured with a
rubber flange. Metals such as brass or steel or any other metal can be used in
the application.
In one embodiment the high durometer material is joined to the rubber so that
the high
durometer material sits 1-3 mm above the inside surface of the tire. In
another embodiment
the high durometer material comprises a flange and is at least in part over
molded by the
rubber material. It is advantageous that the port bonds horizontally to the
inflation lumen
and do not require a barbed fitting to be inserted into the lumen of the
pumping mechanism.
A barbed fitting would be prone to leakage and poor ride characteristics due
to the constant
deformation of the tire during riding and might create the feel of riding over
a bumpy surface.
In one embodiment the tire ports have a fiber layer which strengthens the
casing in the area
where the port pushes through the casing. The fibers may be of nylon, cotton
or any other
load bearing material.
According to the invention, the design has at least one hole through the
casing of the tire.
As described earlier, a check valve is located in the control module which is
near the valve
stem and away from the riding surface. It is desirable to have the check valve
as close as
possible to the end of the pumping mechanism, but this would bring it close to
the riding
surface which would expose the check valve to potential damage. High-pressure
applications
might favor a check valve closer to the end of the pumping mechanism.
Embodiments where
reliability or cost should be optimized, favor the check valve near the valve
stem. The control
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module comprises a mechanism to control the pressure inside the chamber of the
tire or inside
the inner tube. The control module may be partially inside the inner tube or
partially outside
the inner tube. The control module may contain a check valve or it may not.
The current
invention works for tubeless tires as well as tires utilizing inner tubes
In the embodiments in FIGs. 9A-9D and FIGs. 10A-10D, turning the valve stem
adjusts the
pressure in the tire. In one embodiment the valve stem has only one lumen or
passageway
which goes directly to the pumping mechanism. One embodiment uses a diaphragm
valve to
close the passageway so new air cannot enter into the pumping mechanism. The
diaphragm
valve works by employing an elastomeric diaphragm which deforms as the
pressure in the
tire increases. The elastomeric diaphragm is pneumatically connected to the
pressurized
chamber of the inner tube or tire. To stop the entry of new air into the tire
the diaphragm
pushes up against the inlet adjuster thereby closing off the passage to new
air. In one
embodiment the distance between the diaphragm and the inlet adjuster is fixed.
In another
embodiment the inlet adjuster can be turned to increase or decrease the
distance between the
diaphragm of the valve and the inlet adjuster to change the pressure setting
on the system.
In the case where the embodiment uses an inner tube, the control module may be
releasably
attached to the inner tube. In one embodiment the inner tube has three ports.
The first port
connects the inner tube low-pressure port to the tire. The second port
connects the inner tube
high-pressure port to the tire. The third port connects the inner tube to the
control module.
In another embodiment the inner tube has two ports. The two-port embodiment is
used with
the closed-end pumping mechanism. The first port connects the inner tube to
the tire. In this
embodiment there is only one port connecting the inner tube and tire and the
port acts as both
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the low-pressure and high-pressure port. The second port connects the inner
tube to the
control module.
The present invention has now been described in accordance with several
exemplary
embodiments, which are intended to be illustrative in all aspects, rather than
restrictive.
Thus, the present invention is capable of many variations in detailed
implementation, which
may be derived from the description contained herein by a person of ordinary
skill in the art.
All such variations are considered to be within the scope and spirit of the
present invention
as defined by the following claims and their legal equivalents.
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